Chemistry Forum

100ml of a 0.10M NH₃ solution is titrated with a 0.05M HCl solution.
pKb for NH₃ is 4.75

What is the pH of the NH₃ solution before adding HCl?

pKb=-log Kb
Kb=1.778x10^-5

What is the pH after 100ml of HCl is added?

What is the pH after an additional 100ml is added (total HCl v=200ml)?

I'm not sure why I can't seem to get the correct answers for the pH of this buffer solution.

Please help me w/ detailed steps!

Thank you!

Look at some examples of similat tasks. It may help to solve your problem. Keep in mind that NH₄OH is a weak base and not fully dissociated while HCl is a strong acid and it is fully dissociated.
http://answers.yahoo.com/question/index ... 150AA07bFX
http://www.scribd.com/doc/19348945/Solu ... r-solution
http://www.ask.com/questions-about/Nh₄cl-And-Ph